Implement onSkipScanlines() for bmp and wbmp

src/codec/SkBmpStandardCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBmpStandardCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
 #include "SkStream.h"
 
 /*
  * Creates an instance of the decoder
  * Called only by NewFromStream
  */
 SkBmpStandardCodec::SkBmpStandardCodec(const SkImageInfo& info, SkStream* stream,
                                        uint16_t bitsPerPixel, uint32_t numColors,
                                        uint32_t bytesPerColor, uint32_t offset,
                                        SkCodec::SkScanlineOrder rowOrder,
                                        bool isOpaque, bool inIco)
     : INHERITED(info, stream, bitsPerPixel, rowOrder)
     , fColorTable(nullptr)
     , fNumColors(numColors)
     , fBytesPerColor(bytesPerColor)
     , fOffset(offset)
     , fSwizzler(nullptr)
-    , fSrcRowBytes(SkAlign4(compute_row_bytes(this->getInfo().width(), this->bitsPerPixel())))
-    , fSrcBuffer(new uint8_t [fSrcRowBytes])
+    , fSrcBuffer(new uint8_t [this->srcRowBytes()])
     , fIsOpaque(isOpaque)
     , fInIco(inIco)
     , fAndMaskRowBytes(fInIco ? SkAlign4(compute_row_bytes(this->getInfo().width(), 1)) : 0)
 {}
 
 /*
  * Initiates the bitmap decode
  */
 SkCodec::Result SkBmpStandardCodec::onGetPixels(const SkImageInfo& dstInfo,
                                         void* dst, size_t dstRowBytes,
@@ skipping 178 matching lines @@
 
 /*
  * Performs the bitmap decoding for standard input format
  */
 int SkBmpStandardCodec::decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
         const Options& opts) {
     // Iterate over rows of the image
     const int height = dstInfo.height();
     for (int y = 0; y < height; y++) {
         // Read a row of the input
-        if (this->stream()->read(fSrcBuffer.get(), fSrcRowBytes) != fSrcRowBytes) {
+        if (this->stream()->read(fSrcBuffer.get(), this->srcRowBytes()) != this->srcRowBytes()) {
             SkCodecPrintf("Warning: incomplete input stream.\n");
             return y;
         }
 
         // Decode the row in destination format
         uint32_t row = this->getDstRow(y, dstInfo.height());
 
         void* dstRow = SkTAddOffset<void>(dst, row * dstRowBytes);
         fSwizzler->swizzle(dstRow, fSrcBuffer.get());
     }
@@ skipping 16 matching lines @@
         const void* memoryBase = this->stream()->getMemoryBase();
         SkASSERT(nullptr != memoryBase);
         SkASSERT(this->stream()->hasLength());
         SkASSERT(this->stream()->hasPosition());
 
         const size_t length = this->stream()->getLength();
         const size_t currPosition = this->stream()->getPosition();
 
         // Calculate how many bytes we must skip to reach the AND mask.
         const int remainingScanlines = this->getInfo().height() - startScanline - height;
-        const size_t bytesToSkip = remainingScanlines * fSrcRowBytes +
+        const size_t bytesToSkip = remainingScanlines * this->srcRowBytes() +
                 startScanline * fAndMaskRowBytes;
         const size_t subStreamStartPosition = currPosition + bytesToSkip;
         if (subStreamStartPosition >= length) {
             // FIXME: How can we indicate that this decode was actually incomplete?
             return height;
         }
 
         // Create a subStream to pass to decodeIcoMask().  It is useful to encapsulate
         // the memory base into a stream in order to safely handle incomplete images
         // without reading out of bounds memory.
@@ skipping 52 matching lines @@
     }
 }
 
 uint32_t SkBmpStandardCodec::onGetFillValue(SkColorType colorType) const {
     const SkPMColor* colorPtr = get_color_ptr(fColorTable.get());
     if (colorPtr) {
         return get_color_table_fill_value(colorType, colorPtr, 0);
     }
     return INHERITED::onGetFillValue(colorType);
 }